Current trends in ambulatory spine surgery: a systematic review

Moderate burden amongst caregivers posthip arthroscopy linked to younger caregiver age and task load: A cross-sectional survey study

PURPOSE

To evaluate the burden experienced by primary informal caregivers of patients who have undergone hip arthroscopy and to identify factors that predict increased caregiver burden.

METHODS

A cross-sectional study was conducted at a single academic hospital centre, enroling caregivers of patients who underwent hip arthroscopy between November 2018 and November 2023. Caregiver burden was assessed using the Caregiver Burden Inventory (CBI) survey. Multivariable linear regression models were used to identify predictors of caregiver burden, with the global CBI score serving as the primary outcome measure. Secondarily, open-ended survey questions were analyzed qualitatively to elucidate specific challenges and facilitators of caregiving, as reported by the caregivers themselves.

RESULTS

The study involved 99 eligible caregivers (mean [standard deviation] age; 47 [11] years), 58% were female, and 85% were relatives of the patient. The median global CBI score was 13.0 (interquartile range: 8.0-22.4), indicating a moderate burden. Regression analyses demonstrated that younger caregiver age and a higher number of caregiving tasks were significant predictors of increased global burden. Additionally, nonweightbearing status of patients, female gender of caregivers and working full-time statistically significantly increased specific dimensions of caregiver burden.

CONCLUSION

This study highlights the meaningful burden faced by caregivers of patients undergoing hip arthroscopy, despite its minimally invasive nature and outpatient setting. Identified risk factors such as younger caregiver age, female gender of the caregiver, nonweight-bearing status and increased caregiving tasks suggest targeted areas for intervention. The qualitative analysis revealed that caregivers struggle with time management and physical and emotional strain, yet better communication and practical support from healthcare teams could help to alleviate these challenges.

LEVEL OF EVIDENCE

Level IV, prognostic study.

Comparison of the Safety of Inpatient Versus Outpatient Lumbar Fusion : A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic Review and Meta-analysis.

OBJECTIVE

The objective of this study is to synthesize the early data regarding and analyze the safety profile of outpatient lumbar fusion.

SUMMARY OF BACKGROUND DATA

Performing lumbar fusion in an outpatient or ambulatory setting is becoming an increasingly employed strategy to provide effective value-based care. As this is an emerging option for surgeons to employ in their practices, the data is still in its infancy.

METHODS

This study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies that described outcomes of inpatient and outpatient lumbar fusion cohorts were searched from PubMed, Medline, The Cochrane Library, and Embase. Rates of individual medical and surgical complications, readmission, and reoperation were collected when applicable. Patient-reported outcomes (PROMs) were additionally collected if reported. Individual pooled comparative meta-analysis was performed for outcomes of medical complications, surgical complications, readmission, and reoperation. PROMs were reviewed and qualitatively reported.

RESULTS

The search yielded 14 publications that compared outpatient and inpatient cohorts with a total of 75,627 patients. Odds of readmission demonstrated no significant difference between outpatient and inpatient cohorts [OR=0.94 (0.81-1.11)]. Revision surgery similarly was no different between the cohorts [OR=0.81 (0.57-1.15)]. Pooled medical and surgical complications demonstrated significantly decreased odds for outpatient cohorts compared with inpatient cohorts [OR=0.58 (0.34-0.50), OR=0.41 (0.50-0.68), respectively]. PROM measures were largely the same between the cohorts when reported, with few studies showing better ODI and VAS Leg outcomes among outpatient cohorts compared with inpatient cohorts.

CONCLUSION

Preliminary data regarding the safety of outpatient lumbar fusion demonstrates a favorable safety profile in appropriately selected patients, with PROMs remaining comparable in this setting. There is no data in the form of prospective and randomized trials which is necessary to definitively change practice.

Biportal Endoscopic Approach for Lumbar Degenerative Disease in the Ambulatory Outpatient vs Inpatient Setting: A Comparative Study

BACKGROUND

Biportal spinal endoscopy is increasingly utilized for lumbar disc herniations and lumbar stenosis. The objective was to investigate the safety and effectiveness of the technique in the outpatient vs inpatient setting.

METHODS

This is a comparative study of consecutive patients who underwent biportal spinal endoscopy by a single surgeon at a single institution. Demographics, surgical complications, and patient-reported outcomes were prospectively collected and retrospectively analyzed. Statistics were calculated among treatment groups using unpaired t test and χ 2 analysis where appropriate. Statistical significance was determined as P < 0.05.

RESULTS

Eighty-four patients were included, 58 (69.0%) as outpatient, 26 (31.0%) as inpatient. Mean follow-up was 7.5 months. Statistically significant differences in age, American Society of Anesthesiologists classification, and Charleston Comorbidity Index scores were reported between cohorts, with younger and healthier patients undergoing outpatient surgery (P < 0.0001). Outpatients were more likely to have discectomies while inpatients were more likely to have decompressions for stenosis. No significant differences in postoperative complications were found between groups.Both cohorts demonstrated significant improvement in visual analog scale (VAS) back and leg pain scores and Oswestry Disability Index scores (P < 0.001). Outpatients had significantly lower postoperative VAS back pain (P = 0.001) and Oswestry Disability Index scores (P = 0.004) at 5-8 weeks compared with inpatients, but there was no significant difference for VAS leg pain scores at all time points between the cohorts.

CONCLUSIONS

Early results demonstrate that biportal spinal endoscopy can safely and effectively be performed in both inpatient and outpatient settings.

CLINICAL RELEVANCE

Outpatient biportal spinal endoscopy can be performed successfully in well selected patients, which may reduce the financial burden of spine surgery to the U.S. healthcare system.

LEVEL OF EVIDENCE: 3

Intraoperative hypotension in ambulatory surgery centers

STUDY OBJECTIVES

To measure the incidence of intraoperative hypotension (IOH) during surgery in ambulatory surgery centers (ASCs) and describe associated characteristics of patients and procedures.

DESIGN

Retrospective analysis.

SETTING

20 ASCs.

PATIENTS

16,750 patients having non-emergent, non-cardiac surgery; ASA physical status 2 through 4.

INTERVENTIONS

None.

MEASUREMENTS

We assessed incidence of IOH using the definition from the Centers for Medicare & Medicaid Services (CMS) Merit-based Incentive Payment System (MIPS)-mean arterial pressure (MAP) < 65 mmHg for at least 15 cumulative minutes-and three secondary definitions: minutes of MAP <65 mmHg, area under MAP of 65 mmHg, and time-weighted average MAP <65 mmHg.

MAIN RESULTS

30.9% of ASC cases had a MAP <65 mmHg for at least 15 min. The incidence of IOH varied significantly, and was higher among younger adults (age 18-39; 36.2%), females (35.2%), and patients with ASA physical status 2 (32.8%). IOH increased with increasing surgery length, even when time-weighted, and was higher among low complexity (30.6%) than moderate complexity (28.8%) procedures, and highest among high complexity procedures (44.1%).

CONCLUSIONS

There was substantial occurrence of IOH in ASCs, similar to that described in academic hospital settings in previous literature. We hypothesize that this may reflect clinician preference not to intervene in perceived healthy patients or assumptions about ability to tolerate lower blood pressures on behalf of these patients. Future research will determine whether IOH in ACSs is associated with adverse outcomes to the same extent as described in more complex hospital-based surgeries.

Safety considerations with the current ambulatory trends: more complicated procedures and more complicated patients

In the last quarter of a century, the backdrop of appropriate ambulatory and office-based surgeries has changed dramatically. Procedures that were traditionally done in hospitals or patients being admitted after surgery are migrating to the outpatient setting and being discharged on the same day, respectively, at a remarkable rate. In the face of this exponential growth, anesthesiologists are constantly being challenged to maintain patient safety by understanding the appropriate patient selection, procedure, and surgical location. Recently published literature supports the trend of higher, more medically complex patients, and more complicated procedures shifting towards the outpatient arena. Several reasons that may account for this include cost incentives, advancement in anesthesia techniques, enhanced recovery after surgery (ERAS) protocols, and increased patient satisfaction. Anesthesiologists must understand that there is a lack of standardized state regulations regarding ambulatory surgery centers (ASCs) and office-based surgery (OBS) centers. Current and recently graduated anesthesiologists should be aware of the safety concerns related to the various non-hospital-based locations, the sustained growth and demand for anesthesia in the office, and the expansion of mobile anesthesia practices in the US in order to keep up and practice safely with the professional trends. Continuing procedural ambulatory shifts will require ongoing outcomes research, likely prospective in nature, on these novel outpatient procedures, in order to develop risk stratification and prediction models for the selection of the proper patient, procedure, and surgery location.

Is outpatient spine surgery associated with new, persistent opioid use in opioid-naïve patients? A retrospective national claims database analysis

BACKGROUND CONTEXT

Although spine procedures have historically been performed inpatient, there has been a recent shift to the outpatient setting for selected cases due to increased patient satisfaction and reduced cost. Effective postoperative pain management while limiting over-prescribing of opioids, which may lead to persistent opioid use, is critical to performing spine surgery in the outpatient setting.

PURPOSE

To assess if there is an increased risk for new, persistent opioid use between inpatient and outpatient spine procedures.

STUDY DESIGN

Retrospective analysis using national administrative claims database.

PATIENT SAMPLE

A total of 390,049 opioid-naïve patients with a perioperative opioid prescription who underwent an inpatient or outpatient spine surgery.

OUTCOME MEASURES

Patients with perioperative opioid prescriptions who filled ≥ 1 opioid prescription between 90- and 180-days following surgery were defined as new, persistent opioid users.

METHODS

We utilized a claims database to identify opioid-naïve patients who underwent lumbar or cervical fusion, total disc arthroplasty, or decompression procedures. We constructed a multivariable logistic regression to evaluate the association between inpatient versus outpatient surgery and the development of new, persistent opioid use while adjusting for several patient factors.

RESULTS

A total of 19,205 (11.7%) inpatient and 18,546 (8.2%) outpatient patients developed new, persistent opioid use. Outpatient lumbar and cervical spine surgery patients were significantly less likely to develop new, persistent opioid use following surgery compared to inpatient spine surgery patients (OR = 0.71 [95% confidence interval {CI}: 0.69, 0.73], p < .001). Average morphine milligram equivalents (MMEs) (inpatient = 1,476 MME +/- 22.7, outpatient = 1,072 MME +/- 18.5, p < .001) and average MMEs per day (inpatient = 91.6 MME +/- 0.32, outpatient = 77.7 MME +/- 0.28, p < .001) were lower in the outpatient cohort compared to the inpatient.

CONCLUSION

Our results support the shift from inpatient to outpatient spine procedures, as outpatient procedures were not associated with an increased risk for new, persistent opioid use. As more patients become candidates for outpatient spine surgery, predictors of new, persistent opioid use should be considered during risk stratification.

LEVEL OF EVIDENCE

Level III Prognostic Study.

MINI ABSTRACT

We utilized a national administrative claims database to identify opioid-naïve patients who underwent common spine procedures. Outpatient lumbar and cervical spine surgery patients were significantly less likely to be new, persistent opioid users following surgery compared to inpatient spine surgery patients. Our results support the shift to outpatient spine procedures.

Risk stratification of patients undergoing outpatient lumbar decompression surgery

BACKGROUND CONTEXT

Reimbursement has slowly transitioned from a fee-for-service model to a bundled payment model after introduction of the United States Centers for Medicare and Medicaid Services bundled payment program. To minimize healthcare costs, some surgeons are trying to minimize healthcare expenditures by transitioning appropriately selected lumbar decompression patients to outpatient procedure centers.

PURPOSE

To prepare a risk stratification calculator based on machine learning algorithms to improve surgeon's preoperative predictive capability of determining whether a patient undergoing lumbar decompression will meet inpatient vs. outpatient criteria. Inpatient criteria was defined as any overnight hospital stay.

STUDY DESIGN/SETTING

Retrospective single-institution cohort.

PATIENT SAMPLE

A total of 1656 patients undergoing primary lumbar decompression.

OUTCOME MEASURES

Postoperative outcomes analyzed for inclusion into the risk calculator included length of stay.

METHODS

Patients were split 80-20 into a training model and a predictive model. This resulted in 1,325 patients in the training model and 331 into the predictive model. A logistic regression analysis ensured proper variable inclusion into the model. C-statistics were used to understand model effectiveness. An odds ratio and nomogram were created once the optimal model was identified.

RESULTS

A total of 1,656 patients were included in our cohort with 1,078 dischared on day of surgery and 578 patients spending ≥ 1 midnight in the hospital. Our model determined older patients (OR=1.06, p<.001) with a higher BMI (OR=1.04, p<0.001), higher back pain (OR=1.06, p=.019), increasing American Society of Anesthesiologists (ASA) score (OR=1.39, p=.012), and patients with more levels decompressed (OR=3.66, p<0.001) all had increased risks of staying overnight. Patients who were female (OR=0.59, p=.009) and those with private insurance (OR=0.64, p=.023) were less likely to be admitted overnight. Further, weighted scores based on training data were then created and patients with a cumulative score over 118 points had a 82.9% likelihood of overnight. Analysis of the 331 patients in the test data demonstrated using a cut-off of 118 points accurately predicted 64.8% of patients meeting inpatient criteria compared to 23.0% meeting outpatient criteria (p<0.001). Area under the curve analysis showed a score greater than 118 predicted admission 81.4% of the time. The algorithm was incorporated into an open access digital application available here: https://rothmanstatisticscalculators.shinyapps.io/Inpatient_Calculator/?_ga=2.171493472.1789252330.1671633274-469992803.1671633274 CONCLUSIONS: Utilizing machine-learning algorithms we created a highly reliable predictive calculator to determine if patients undergoing outpatient lumbar decompression would require admission. Patients who were younger, had lower BMI, lower preoperative back pain, lower ASA score, less levels decompressed, private insurance, lived with someone at home, and with minimal comorbidities were ideal candidates for outpatient surgery.

Opioid prescription trends after ambulatory anterior cervical discectomy and fusion

BACKGROUND CONTEXT

Opioid utilization has been well studied for inpatient anterior cervical discectomy and fusion (ACDF). However, the amount and type of opioids prescribed following ambulatory ACDF and the associated risk of persistent use are largely unknown.

PURPOSE

To characterize opioid prescription filling following single-level ambulatory ACDF compared with inpatient procedures.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Opioid-naive patients who underwent ambulatory (no overnight stay) or inpatient single-level ACDF from 2011 to 2019 were identified from a national insurance database.

OUTCOME MEASURES

Rate, amount, and type of perioperative opioid prescription.

METHODS

Opioid-naive patients who underwent ambulatory (no overnight stay) or inpatient single-level ACDF from 2011 to 2019 were identified from a national insurance database. Perioperative opioids were defined as opioid prescriptions 30 days before and 14 days after the procedure. Rate, amount, and type of opioid prescription were characterized. Multivariable analyses controlling for any differences in demographics and comorbidities between the two treatment groups were utilized to determine any association between surgical setting and persistent opioid use (defined as the patient still filling new opioid prescriptions >90 days postoperatively).

RESULTS

A total of 42,521 opioid-naive patients were identified, of which 2,850 were ambulatory and 39,671 were inpatient. Ambulatory ACDF was associated with slightly increased perioperative opioid prescription filling (52.7% vs 47.3% for inpatient procedures; p<.001). Among the 20,280 patients (47.7%) who filled perioperative opioid prescriptions, the average amount of opioids prescribed (in morphine milligram equivalents) was similar between ambulatory and inpatient procedures (550 vs 540, p=.413). There was no association between surgical setting and persistent opioid use in patients who filled a perioperative opioid prescription, even after controlling for comorbidities, (adjusted odds ratio, 1.15, p=.066).

CONCLUSIONS

Ambulatory ACDF patients who filled perioperative opioid prescriptions were prescribed a similar amount of opioids as those undergoing inpatient procedures. Further, ambulatory ACDF does not appear to be a risk factor for persistent opioid use. These findings are important for patient counseling as well as support the safety profile of this new surgical pathway.

Choose Wisely: Surgical Selection of Candidates for Outpatient Anterior Cervical Surgery Based on Early Complications Among Inpatients

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) are attractive targets for transition to the outpatient setting. We assessed the prevalence of rapid responses and major complications in the inpatient setting following 1 or 2-level ACDFs and CDAs. We evaluated factors that may place patients at greater risk for a rapid response or a postoperative complication.

METHODS

This was an institutional review board-approved, retrospective cohort study of adults undergoing 1 or 2-level ACDF or CDA at 1 hospital over a 2-year period (2018 and 2019). Data on patient demographic characteristics, surgical procedures, and comorbidities were collected. Rapid response events were identified by hospital floor staff and involved acute changes in a patient's clinical condition. Complications were events that were life-threatening, required an intervention, or led to delayed hospital discharge.

RESULTS

In this study, 1,040 patients were included: 888 underwent ACDF and 152 underwent CDA. Thirty-six patients (3.5%) experienced a rapid response event; 22% occurred >24 hours after extubation. Patients having a rapid response event had a significantly higher risk of developing a complication (risk ratio, 10; p < 0.01) and had a significantly longer hospital stay. Twenty-four patients (2.3%) experienced acute complications; 71% occurred >6 hours after extubation. Patients with a complication were older and more likely to be current or former smokers, have chronic obstructive pulmonary disease, have asthma, and have an American Society of Anesthesiologists (ASA) score of >2. The length of the surgical procedure was significantly longer in patients who developed a complication. All patients who developed dysphagia had a surgical procedure involving C4-C5 or more cephalad. Patients with a rapid response event or complication were more commonly undergoing revision surgical procedures.

CONCLUSIONS

Rapid response and complications are uncommon following 1 or 2-level ACDFs or CDAs but portend a longer hospital stay and increased morbidity. Revision surgical procedures place patients at higher risk for rapid responses and complications. Additionally, older patients, patients with chronic obstructive pulmonary disease or asthma, patients who are current or former smokers, and patients who have an ASA score of ≥3 are at increased risk for postoperative complications.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Spine Surgery Complications in the Ambulatory Surgical Center Setting: Systematic Review

STUDY DESIGN

This was a systematic review study.

PURPOSE

This study aims to review current literature to determine the rates of complications in relation to spine surgery in ambulatory surgery centers (ASC).

BACKGROUND

Recent improvements in anesthesia, surgical techniques, and technological advances have facilitated a rise in the use of ASC. Despite the benefits and lower costs associated with ASCs, there is inconsistent reporting of complication rates.

METHODS

This systematic review was completed utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Pertinent studies were identified through Embase and PubMed databases using the search string ((("ambulatory surgery center") AND "spine surgery") AND "complications"). Articles were excluded if they did not report outpatient surgery in an ASC, did not define complications, were in a language other than English, were non-human studies, or if the articles were classified as reviews, book chapters, single case reports, or small case series (≤10 patients). The primary outcome was the frequency of complications with respect to various categories.

RESULTS

Our query identified 150 articles. After filtering relevance by title, abstract, and full text, 22 articles were included. After accounting for 2 studies that were conducted on the same study sample, a total of 11,245 patients were analyzed in this study. The most recent study reported results from May 2019. While 5 studies did not list their surgical technique, studies reported techniques including open (6), minimally invasive surgery (2), endoscopic (4), microsurgery (1), and combined techniques (4). The following rates of complications were determined: cardiac 0.29% (3/1027), vascular 0.25% (18/7116), pulmonary 0.60% (11/1839), gastrointestinal 1.12% (2/179), musculoskeletal/spine/operative 0.59% (24/4053), urologic 0.80% (2/250), transient neurological 0.67% (31/4616), persistent neurological 0.61% (9/1479), pain related 0.57% (20/3479), and wound site 0.68% (28/4092).

CONCLUSIONS

After literature review, this is the first study to comprehensively analyze the current state of literature reporting on the complication profile of all ASC spine surgery procedures. The most common complications were gastrointestinal (1.12%) and the most infrequent were vascular (0.25%). Case reports varied significantly with regard to the type and rate of complications reported. This study provides complication profiles to assist surgeons in counseling patients on the most realistic expectations.

Association of Medicaid expansion under the Affordable Care Act with access to elective spine surgical care

OBJECTIVE

The Affordable Care Act expanded Medicaid eligibility in many states, improving access to some forms of elective healthcare in the United States. Whether this effort increased access to elective spine surgical care is unknown. This study's objective was to evaluate the impact of Medicaid expansion under the Affordable Care Act on the volume and payer mix of elective spine surgery in the United States.

METHODS

This study evaluated elective spine surgical procedures performed from 2011 to 2016 and included in the all-payer State Inpatient Databases of 10 states that expanded Medicaid access in 2014, as well as 4 states that did not expand Medicaid access. Adult patients aged 18-64 years who underwent elective spine surgery were included. The authors used a quasi-experimental difference-in-difference design to evaluate the impact of Medicaid expansion on hospital procedure volume and payer mix, independent of time-dependent trends. Subgroup analysis was conducted that stratified results according to cervical fusion, thoracolumbar fusion, and noninstrumented surgery.

RESULTS

The authors identified 218,648 surgical procedures performed in 10 Medicaid expansion states and 118,693 procedures performed in 4 nonexpansion states. Medicaid expansion was associated with a 17% (95% CI 2%-35%, p = 0.03) increase in mean hospital spine surgical volume and a 23% (95% CI -0.3% to 52%, p = 0.054) increase in Medicaid volume. Privately insured surgical volumes did not change significantly (incidence rate ratio 1.13, 95% CI -5% to 34%, p = 0.18). The increase in Medicaid volume led to a shift in payer mix, with the proportion of Medicaid patients increasing by 6.0 percentage points (95% CI 4.1-7.0, p < 0.001) and the proportion of private payers decreasing by 6.7 percentage points (95% CI 4.5-8.8, p < 0.001). Although the magnitude of effects varied, these trends were similar across procedure subgroups.

CONCLUSIONS

Medicaid expansion under the Affordable Care Act was associated with an economically and statistically significant increase in spine surgery volume and the proportion of surgical patients with Medicaid insurance, indicating improved access to care.

Preoperative Peripheral Nerve Blocks in Orthopaedic Trauma Surgery: A Guide to Diagnosis-Based Treatment

Perioperative pain management remains an important focus of both patient and provider attention in orthopaedic trauma surgery. There is a constant effort to improve pain management while decreasing opioid consumption, and peripheral nerve blocks are a safe and effective way to achieve these two goals. This is particularly relevant because more procedures are being done in outpatient surgery centers, and the need to safely provide analgesia without the systemic risk of opioid medications is paramount. The primary goal of this article was to describe the diagnosis-based approach for the utilization of preoperative peripheral nerve blocks in perioperative care for orthopaedic trauma surgery procedures based on the experience and current practice at our center.

Comparison of the Safety of Outpatient Cervical Disc Replacement With Inpatient Cervical Disc Replacement: A Systematic Review and Meta-Analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVES

Outpatient cervical disc replacement (CDR) has been performed with an increasing trend in recent years. However, the safety profile surrounding outpatient CDR remains insufficient. The present study systematically reviewed the current studies about outpatient CDR and performed a meta-analysis to evaluate the current evidence on the safety of outpatient CDR as a comparison with the inpatient CDR.

METHODS

We searched the PubMed, Embase, Web of Science, and Cochrane Library databases comprehensively up to April 2020. Patient demographic data, overall complication, readmission, returning to the operation room, operating time were analyzed with the Stata 14 software and R 3.4.4 software.

RESULTS

Nine retrospective studies were included. Patients underwent outpatient CDR were significantly younger (mean difference [MD] = -1.97; 95% CI -3.80 to -0.15; P = .034) and had lower prevalence of hypertension (OR = 0.68; 95% CI 0.53-0.87; P = .002) compared with inpatient CDR. The pooled prevalence of overall complication was 0.51% (95% CI 0.10% to 1.13%) for outpatient CDR. Outpatient CDR had a 59% reduction in risk of developing complications (OR = 0.41; 95% CI 0.18-0.95; P = .037). Outpatient CDR showed significantly shorter operating time (MD = -18.37; 95% CI -25.96 to -10.77; P < .001). The readmission and reoperation rate were similar between the 2 groups.

CONCLUSIONS

There is a lack of prospective studies on the safety of outpatient CDR. However, current evidence shows outpatient CDR can be safely performed under careful patient selection. High-quality, large prospective studies are needed to demonstrate the generalizability of this study.

Using a national surgical database to predict complications following posterior lumbar surgery and comparing the area under the curve and F1-score for the assessment of prognostic capability

BACKGROUND

With spinal surgery rates increasing in North America, models that are able to accurately predict which patients are at greater risk of developing complications are highly warranted. However, the previously published methods which have used large, multi-centre databases to develop their prediction models have relied on the receiver operator characteristics curve with the associated area under the curve (AUC) to assess their model's performance. Recently, it has been found that a precision-recall curve with the associated F1-score could provide a more realistic analysis for these models.

PURPOSE

To develop a logistic regression (LR) model for the prediction of complications following posterior lumbar spine surgery and to then assess for any difference in performance of the model when using the AUC versus the F1-score.

STUDY DESIGN

Retrospective review of a prospective cohort.

PATIENT SAMPLE

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) registry was used. All patients that underwent posterior lumbar spine surgery between 2005 to 2016 with appropriate data were included.

OUTCOME MEASURES

Both the AUC and F1-score were utilized to assess the prognostic performance of the prediction model.

METHODS

In order to develop the LR model used to predict a complication during or following spine surgery, 19 variables were selected by three orthopedic spine surgeons from the NSQIP registry. Two datasets were developed for this analysis: (1) an imbalanced dataset, which was taken directly from the NSQIP registry, and (2) a down-sampled set. The purpose of the down-sampled set was to balance the data in order to evaluate whether balancing the data had an effect on model performance. The AUC and F1-score were applied to both of these datasets.

RESULTS

Within the NSQIP database, 52,787 spine surgery cases were identified of which only 10% of these cases had complications during surgery. Applying the LR model showed a large difference between the AUC (0.69) and the F1 score (0.075) on the imbalanced dataset. However, no major differences existed between the AUC and F1-score when the data was balanced and the LR model was reapplied (0.69 and 0.62, AUC and F1-score, respectively).

CONCLUSIONS

The F1-score detected a drastically lower performance for the prediction of complications when using the imbalanced data, but detected a performance similar to the AUC level when balancing techniques were utilized for the dataset. This difference is due to a low precision score when many false positive classifications are present, which is not identified when using the AUC value. This lowers the utility of the AUC score, as many of the datasets used in medicine are imbalanced. Therefore, we recommend using the F1-score on large, prospective databases when the data is imbalanced with a large amount of true negative classifications.

Comparison of Two-level Cervical Disc Replacement Versus Two-level Anterior Cervical Discectomy and Fusion in the Outpatient Setting

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to evaluate the safety of two-level cervical disc replacement (CDR) in the outpatient setting.

SUMMARY OF BACKGROUND DATA

Despite growing interest in CDR, limited data exist evaluating the safety of two-level CDR in the outpatient setting.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was queried for all two-level anterior cervical discectomy and fusion (ACDF) and CDR procedures between 2015 and 2018. Demographics, comorbidities, and 30-day postoperative complication rates of outpatient two-level CDR were compared to those of inpatient two-level CDR and outpatient two-level ACDF. Radiographic data are not available in the NSQIP.

RESULTS

A total of 403 outpatient CDRs were compared to 408 inpatient CDRs and 4134 outpatient ACDFs. Outpatient CDR patients were older and more likely to have pulmonary comorbidities compared to inpatient CDR (P < 0.03). Outpatient CDR patients were less likely to have an American Society of Anesthesiologists class ≥2 and have hypertension compared to outpatient ACDF patients (P < 0.0001). Outpatient CDR had a lower 30-day readmission rate (0.5% vs. 2.5%, P = 0.02) and lower 30-day reoperation rate (0% vs. 1%, P = 0.047) compared to inpatient CDR. Outpatient CDR had a lower readmission rate (0.5% vs. 2.1%, P = 0.03) compared to outpatient ACDF, but there was no difference in reoperation rates between the two procedures (0% vs. 0.8%, P = 0.07). Outpatient CDR had an overall complication rate of 0.2%, inpatient CDR had a complication rate of 0.9%, and outpatient ACDF had a complication rate of 1.3%. These differences were not significant.

CONCLUSION

To our knowledge, this is the largest multicenter study examining the safety of two-level outpatient CDR procedures. Outpatient two-level CDR was associated with similarly safe outcomes when compared to inpatient two-level CDR and outpatient two-level ACDF. This suggests that two-level CDR can be performed safely in the outpatient setting.Level of Evidence: 3.

Outcomes of Same-Day Orthopedic Surgery: Are Spine Patients More Likely to Have Optimal Immediate Recovery From Outpatient Procedures?

BACKGROUND

Spinal surgery is associated with an inherently elevated risk profile, and thus far there has been limited discussion about how these outpatient spine patients are benefiting from these same-day procedures against other typical outpatient orthopedic surgeries.

METHODS

Orthopedic patients who received either inpatient or outpatient surgery were isolated in the American College of Surgeons National Surgical Quality of Improvement Program (2005-2016). Patients were stratified by type of orthopedic surgery received (spine, knee, ankle, shoulder, or hip). Mean comparisons and chi-squared tests assessed basic demographics. Perioperative complications were analyzed via regression analyses in regard to their principal inpatient or outpatient orthopedic surgery received.

RESULTS

This study included 729 480 surgical patients: 32.5% received spinal surgery, 36.5% knee, 24.1% hip, 4.9% shoulder, and 1.7%ankle. Of those who received a spinal procedure, 74.7% were inpatients (IN), and 25.3% were outpatients (OUT): knee: 96.1% IN, 3.9% OUT; hip:98.9% IN, 1.1% OUT; ankle: 29% IN, 71% OUT; and shoulder: 52.6% IN, 47.6% OUT. Hip patients were the oldest, and knee patients had the highest body mass index out of the orthopedic groups (P < .00). Spine IN patients experienced more complications than the other orthopedic groups and had the lowest OUT complications(both P < .05). This same trend of having higher IN complications than OUT complications was identified for hip, shoulder, and knee. However, ankle procedures had greater OUT procedure complications than IN (P < .05). After controlling for age, body mass index, and Charlson Comorbidity Index, IN procedures, such as knee, hip, spine, and shoulder, were significantly associated with experiencing postoperative complications. From 2006 to 2016, IN and OUT surgeries were significantly different among complications experienced for all of the orthopedic groups (P < .05) with complications decreasing for IN and OUT patients by 2016.

CONCLUSIONS

Over the past decade, spine surgery has decreased in complications for IN and OUT procedures along with IN/OUT knee, ankle, hip, and shoulder procedures, reflecting greater tolerance for risk in an outpatient setting.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Despite the increase in riskier spine procedures, complications have decreased over the years. Surgeons should aim to continue to decrease inpatient spine complications to the level of other orthopedic surgeries.

Multimodal Analgesic Management for Cervical Spine Surgery in the Ambulatory Setting

BACKGROUND

Patient selection and analgesic techniques, such as the multimodal analgesic (MMA) protocol, aid in ambulatory surgical center (ASC) cervical spine surgery. The purpose of this case series is to characterize patients undergoing anterior cervical discectomy and fusion (ACDF) and total cervical disc replacement (CDR) in an ASC with an enhanced MMA protocol.

METHODS

A prospectively maintained registry was retrospectively reviewed for cervical surgeries between May 2013 and August 2019. Inclusion criteria included ASC patients who underwent single-level or multilevel CDR or ACDF using an MMA protocol. Baseline, intraoperative, and postoperative characteristics were recorded, including length of stay, visual analog scale pain scores, neck disability index, complications, and narcotics administered.

RESULTS

A total of 178 patients met inclusion criteria with 125 single-level, 52 two-level, and 1 three-level procedure. Of those patients, 127 underwent ACDF and 51 underwent CDR. The longest procedure was 95 minutes and the mean length of stay was 6.1 hours, with 2 patients requiring hospital admission. All other patients were discharged within 10 hours. One of the admitted patients experienced a postoperative seizure that was later determined to be secondary to drug use and serotonin syndrome. The second patient developed an anterior cervical hematoma 5 hours postoperatively, which was immediately evacuated. The patient was admitted for observation and discharged the next day.

CONCLUSION

In our study, patients experienced considerable improvement in disability scores, with a low likelihood of postoperative complications. A safe and effective MMA protocol may help facilitate anterior cervical surgery in the outpatient setting.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Transitioning anterior cervical discectomy and fusions to the ASC requires an appropriate MMA protocol. Our findings reveal that an enhanced MMA protocol will help improve disability scores while keeping the likelihood of postoperative complications low. This supports the ASC setting for cervical spine procedures in appropriate patient populations.

Are outpatient three- and four-level anterior cervical discectomies and fusion safe?

BACKGROUND CONTEXT

The safety of outpatient one- and two-level anterior cervical discectomy and fusion (ACDF) has been validated in a number of recent studies. However, recent advancements in anesthetic and surgical technique have rendered procedures previously only performed in an inpatient setting, such as three- and four-level ACDF, potentially amenable to outpatient management.

PURPOSE

The present study aimed to investigate the safety of outpatient three- and four-level ACDF.

STUDY DESIGN

Retrospective cohort study PATIENT SAMPLE: The National Surgical Quality Improvement Program - a large, prospectively-collected registry - was queried to identify patients undergoing three- and four-level ACDF in an inpatient and outpatient setting.

OUTCOME MEASURES

The rates of total complications, perioperative blood transfusion, and unplanned hospital readmission in three- and four-level ACDF by inpatient or outpatient surgery status.

METHODS

Baseline patient characteristics and 30-day outcomes were tabulated and compared by inpatient or outpatient status using bivariate analysis. A multivariate analysis was also employed to adjust for differences in baseline patient characteristics when comparing outcomes, and was also used to identify independent predictors of complications and readmissions in patients undergoing three- and four-level ACDF.

RESULTS

In total 3,441 patients underwent three- or four-level ACDF, with 2,718 (79.0%) procedures occurring inpatient and 723 (21.0%) outpatient. Of patients undergoing outpatient ACDF, 596 patients (82.4%) underwent a three-level and 127 patients (17.6%) underwent four-level procedures. There was an increase in the utilization of outpatient procedures, increasing from 7.0% to 32.9% between 2011 and 2018. Patients undergoing outpatient surgery were younger, white, more likely to have three-level fusions (vs four-level), had a lower American Society of Anesthesiologists (ASA) classification, and were less likely to have a history of diabetes mellitus or dependent functional status. Among the inpatient and outpatient cohorts, there was no significant difference in the rates of total complications (4.49% vs 2.49%) or unplanned readmissions (4.96% vs 3.72%). Increasing age, operative duration, and ASA classification were independent predictors of complications and readmissions, however, inpatient or outpatient surgery status and number of levels fused was not.

CONCLUSIONS

This present study represents one of the largest cohorts of patients undergoing outpatient three- and four-level ACDF. Outpatient multilevel ACDF is performed in younger and healthier patients, with three-level procedures more commonly the four-level. There was no observed increased rates of total complications or readmissions in patients undergoing outpatient relative to inpatient surgery, however, we did identify increased age, operative duration, and ASA classification as independent predictors of these complications. Patient selection for outpatient procedures is of the highest importance, and future studies developing reproducible selection criteria are warranted.

High-risk surgical procedures and semi-emergent surgical procedures for ambulatory surgery

PURPOSE OF REVIEW

This review evaluates more complex surgical procedures to see whether they might be suitable for ambulatory surgery. Operations that have shown an increasing daycase rate in England include thyroidectomy, joint arthroplasty, spinal surgery and hysterectomy, and these procedures are evaluated. Similarly, there have been recent developments in the management of nonelective ambulatory surgery with more timely throughput and home discharge for suitable patients.

RECENT FINDINGS

Caveats on patient selection with the development of focussed educational programmes about the proposed operation have assisted with the development of shorter discharge times. Strict antiemetic guidelines, multimodal analgesic protocols and postoperative multidisciplinary follow-up are core components of the pathway for effective ambulatory management. Communication after discharge should include phone calls from the Ambulatory Unit and easy access to the medical staff who conducted their operation.

SUMMARY

There should be no reason why more complex surgical operations could not be included in a day surgery armamentarium. Similarly, the evidence for more effective use of timely emergency care with shortened length of stay is increasing.